1. The Field of the Invention
The present invention pertains to beam pumping wells and, more particularly, to a bottom discharge valve for use in beam pumping wells having a reciprocating downhole pump.
2. The Prior Art
Bottom discharge valves are typically used with a reciprocating downhole pump portion of a beam pumping well. The bottom discharge valve is mounted just above the standing valve. Prior art bottom discharge valves have included three main parts. The first part is a bottom discharge valve body which oftentimes is very restrictive to the free flow of fluid from the well. The second part is a plunger cage. The third part is a long sleeve which surrounds the plunger cage. Typically the long sleeve is threaded onto the bottom discharge valve body. When the parts are assembled together, their length generally exceeds 12 inches.
The reason a bottom discharge valve is used is to push some of the fluid between the tubing and the pump barrel from the pump barrel in order to keep any sand contained in the fluid from settling out between the pump barrel and the tubing. Sand settling between the pump barrel and the tubing may actually cause the pump to stick in the tubing.
For a description of the operation of reciprocating pumps of the type used for producing fluids from subsurface wells, reference is made to my U.S. Pat. No. 6,368,084, the disclosure of which is incorporated herein by reference.
The bottom discharge valve of the present invention is located on the bottom of the pump barrel just above the standing valve. The externally threaded pin end of the standing valve threads into the lower internally threaded portion of the bottom discharge valve of the present invention. The externally threaded or pin end of the disclosed bottom discharge valve is large enough to allow the plunger cage or the traveling valves to actually stroke into the hollow portion of the neck or pin end of the disclosed bottom discharge valve.